Selloffs are only fun if you’re a buyer. Recent market downside for master limited partnerships (MLP) in general has left a number of very safe Portfolio Holdings on the bargain counter for those who don’t already own them.

For that reason, both of this month’s Best Buys are Conservative Holdings: Enterprise Products Partners LP (NYSE: EPD) and Kinder Morgan Energy Partners LP (NYSE: KMP).

Both trade at their most attractive levels all year, Enterprise Products 11 percent off its 52-week high and Kinder Morgan 14 percent below.

Enterprise Products’ market capitalization of USD44.4 billion and Kinder Morgan’s market cap of USD27.6 billion are in the top rank of MLPs by size. So are their records for steadily increasing distributions.

Enterprise Products’ 2.4 percent increase announced this fall marks a sharp acceleration from the prior quarter’s 1.2 percent boost. And it’s the 35th consecutive quarterly increase as well. Kinder Morgan’s 2.4 percent bump is the third consecutive robust jump and is in line with management’s plans for at least 7 percent annual growth going forward.

Strong distribution growth is part and parcel of managements’ success taking the pair to a whole new level of scale that makes both MLPs potential partners for any North American venture.

That’s likely to prove an extremely valuable attribute going forward as larger producers account for a greater percentage of new energy development.

Kinder Morgan recently guided toward at least USD5.28 per unit in total distributions for 2013, a 6 percent increase over 2012.

This will be financed by the expected purchase of 50 percent of the El Paso Natural Gas Pipeline and another half stake in midstream assets currently wholly owned by general partner Kinder Morgan Inc (NYSE: KMI). Kinder Morgan Inc completed the acquisition last year of the former El Paso Corp, including the general partner interest of El Paso Pipeline Partners LP (NSYE: EPB).

Kinder Morgan’s strategy since its origins in the 1990s has been to expand its ownership of fee-based assets, generating cash flows not directly impacted by commodity price swings. This remains its focus now, even as it has expanded operations throughout North America’s most prolific hydrocarbon reserves. Current operations extend to every major shale play on the continent as well as the Alberta oil sands.

Not only do fee-based operations insulate the MLP from energy price swings. But its reach and financial power now ensure it will be a major player as North American energy output ramps up over the next decade.

The primary knock on the MLP in recent years is that Kinder Morgan Inc takes too much of a general partner cut. But the 6.5 percent yield and locked-in distribution growth are more than just compensation for limited partners.

Buy Kinder Morgan Energy Partners up to USD86 if you don’t already own it.

Enterprise Products subsumed its general partner interest, a move that helped reduce its cost of equity capital.

Debt capital too is dirt cheap, in fact ridiculously so with the company’s bonds maturing in 2068 now yielding just 4.25 percent to maturity.

That’s not likely to last forever. But for now extremely low financing costs give the MLP the ability to keep expanding its fee-based assets at a feverish clip.

Enterprise Products’ Seaway pipeline is set to come on stream in early January, helping relieve a longtime bottleneck at the Cushing, Oklahoma, hub that’s hurt North American crude oil prices.

Meanwhile, the MLP has launched an expansion project for a natural gas liquids system to be added in mid-2013.

Analyst opinion on Enterprise Products is 20 “buys” versus three “holds” and zero “sells.” Kinder Morgan’s numbers are somewhat less bullish but still positive, with six “buys,” 14 “holds” and no “sells.”

Both are heavily owned by their insiders, with the Duncan family (Enterprise Products) and Richard Kinder very large owners. That means they’re focused on the long term, even as their size enables them to weather almost anything.

My longstanding advice has been to buy Enterprise Products Partners anytime the partnership’s units trade under USD55.